except tuple
- Python course
- Intermediate
- Lesson 83/116
- 5 min
Learn tuple exceptions with except (A, B).
Multiple types with except tuple
You can list several error types in a single except block as a parenthesized tuple: except (ValueError, TypeError):. This block catches both types; it's a shortcut when you want to do the same thing.
Using a tuple reduces code repetition. It works for three or more types too: except (ValueError, TypeError, KeyError):. To access the error object you add as e; that's the next lesson.
Why are parens required?
The form except ValueError, TypeError: was valid in Python 2 but is a syntax error in Python 3. Parens are required: except (ValueError, TypeError):. This change is for readability and consistency.
Without parens Python treats the part after the comma as another syntax. So in Python 3 code you always use a parenthesized tuple. Old Python 2 code may show the paren-free form; modern Python won't run it.
Practice Catch two types with a tuple except
In a try block call value = int("abc"). Below it add except (ValueError, TypeError): and inside it write print("Caught"). ValueError matches so this block runs.
Starter code
# Try a number conversion in a try block
# Catch ValueError and TypeError in one blockSample solution
# Call int("abc") in a try block
try:
value = int("abc")
# Catch with except (ValueError, TypeError):
except (ValueError, TypeError):
print("Caught")Expected output
Caught
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Complete the tuple except
try:
value = int("x")
except ____:
print("Error")try:
value = int("x")
except (ValueError, TypeError):
print("Error")Explanation: Multi-type except uses a parenthesized tuple.
2 What does except (A, B, C): do?
- Catches any of A, B or C Correct answer
- Catches only type A
- Raises three errors in order
- Catches only the last type
Explanation: If any type in the tuple matches, the block runs.
3 Match the except tuple concepts
| Term | Meaning |
|---|---|
(A, B) |
Multi-type tuple |
parens |
Required in Python 3 |
ValueError |
Invalid value |
TypeError |
Wrong type |